96 volvo 850 speedometer somtimes works then it drops to 0

This is a common problem with 850s. The speedometer is driven electrically, while the odometer is mechanical.

There's a tiny little gear inside the odometer that runs it from a motor; it's no longer tied directly to a speedometer cable like older models. What happens is the gear gets old and brittle and loses teeth, at which point it can no longer turn the odometer.

My wife's '96 850 had the same issue when I got it, and a little internet research turned up the answer above. There are companies that make replacement gears you can buy fairly cheaply, but it does require a fair amount of mechanical aptitude to pull the instrument panel and disassemble the speedometer assembly.

One note of caution that I learned the hard way: you have to take the front cover off the instrument panel, exposing all of the gauges. Be very careful not to disturb the position of those little needles; I ended up messing up the gas gauge, speedometer and temperature gauge, and it took a lot of trial and error to get them put back in so they showed the right readings.

If I recall correctly, I found instructions for doing the gear replacement online, but it's been so long that I don't have the web page(s) I found any more. A lot of times the manufacturer of the replacement gears have instructions on their web sites.

IPD USA sells them and has instructions.

850 Odometer Gear

At the transmission.

If you want to solve your problem, click on the link I attached
https://www.reliable-store.com/products/volvo-850-service-repair-manual-1992-1996-download

there is a head lamp switch mounted to the steering column. it has died. to access it you have to remove the cover under the dash. remove the four bolts hold the steering column and let it drop down. find the switch usually behind and to the side of the ignition switch. there will be a rod giong to it from the handle. remove and replace the switch and assemble in reverse order

You have a broken odometer gear wheel which is very delicate and hard to change it cost less than fifty bucks but it will take a volvo expert one hour or more to change if your not volvo acquinted dont attempt to fix it.you will mess the dash board

Hi
most likely the mechanism has failed at the back of the instrument panel, Its not digital is it? just normal type. also sometimes the speedo cable pull back slightly into the dash the speed will still show but if it is not tight up against the back panel then sometimes the miles will not turn. You will have to remove the clocks to be sure.

Regards

Dan

There are actually two gears that you need to replace, a large one and then smaller one that rides inside it. You can purchase them both at www.fcpgroton.com These can also sometimes affect the operation of your speedometer. Do you by chance have an ABS and TRACS light on? If so the speedometer issue may be related to your ABS controller.

The spedo cable from the transmission into the back of you gauge cluster either came out, or broke.

Multiply anything you see on the speedo by 6, and drop the 0

40km = 24mph
50km = 30mph
60km = 36 mph
70km = 42mph
80km = 48mph
yada...yada... 100km - 60
EX and cheap!

back of engine at the very bottom on the trans where the axle mount